JP3272907B2 - Polymer scale adhesion inhibitor and method for producing polymer using the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer scale inhibitor for use in the polymerization of a monomer having an ethylenically unsaturated double bond, and a method for producing a polymer using the same.

[0002]

2. Description of the Related Art It is known that when a monomer having an ethylenically unsaturated double bond is polymerized, a polymer scale easily adheres to the inner wall surface of the polymerization vessel. If the polymer scale adheres, the yield of the polymer, the cooling capacity of the polymerization vessel, etc. decrease, and this polymer scale peels off and mixes into the polymer, resulting in molding obtained by molding such a polymer. The disadvantage is that the quality of goods is reduced. Also,
The operation of removing the adhered polymer scale requires not only excessive labor and time, but also unreacted monomers present in the polymer scale may cause harm to the human body.

Conventionally, for example, in a method of suspension polymerization of a vinyl halide monomer, in order to prevent the polymer scale from adhering to the inner wall surface of the polymerization vessel, the polymer scale adheres to the inner wall surface of the polymerization vessel. A method for forming a coating film composed of an inhibitor is known. Examples of the polymer scale adhesion inhibitor used in this method include, for example, specific polar compounds (Japanese Patent Publication No. 45-30343), dyes or pigments (Japanese Patent Publication No. 45-3).
Nos. 0835 and 52-24953), aromatic amine compounds (JP-A-51-50887), reaction products of phenol compounds with aromatic aldehydes (JP-A-55-54317), aromatics Amine condensates (Japanese Patent Publication No. 60-30681) are known. However, coatings composed of these polymer scale adhesion inhibitors are, for example, styrene, α-methylstyrene,
There is a disadvantage that it is easily dissolved in monomers such as acrylates, acrylonitrile, and vinyl acetate. Therefore,
When polymerizing a monomer mixture containing these monomers, it is necessary to effectively prevent the polymer scale from adhering to the inner wall surface of the polymerization vessel even when the polymer scale adhesion inhibitor is used. Can not. In particular, when the concentration of the monomer is high, or when the polymerization time is long even when the concentration is low, the polymer scale tends to adhere.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to polymerize a monomer mixture having an ethylenically unsaturated double bond mainly composed of the above-mentioned monomer such as styrene. An object of the present invention is to provide a polymer scale adhesion inhibitor capable of sufficiently preventing the adhesion of a polymer scale to an inner wall surface of a polymerization vessel or the like, and a method for producing a polymer using the same.

[0005]

That is, the present invention provides a polymer for polymerizing a monomer having an ethylenically unsaturated double bond containing a reaction product of a condensate of an aminonaphthalene compound and p-benzoquinone. Provide a coalescing scale adhesion inhibitor.

Further, the present invention provides a polymer comprising a step of polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel having a coating film having an anti-adhesion property on the inner wall of the polymerization vessel. The method for producing a polymer according to the above, wherein the coating film having the polymer scale adhesion preventing property comprises the polymer scale adhesion preventing agent. Hereinafter, the present invention will be described in detail.

(Polymer scale adhesion inhibitor) The polymer scale adhesion inhibitor of the present invention contains a reaction product of the condensate of the aminonaphthalene compound and p-benzoquinone. Examples of the condensate of the aminonaphthalene compound used in the reaction product include, for example, the following general formula:

[0008]

Embedded image

Wherein R ¹ is -H, -COOH, -OH, -NH
Is a monovalent atom or group selected from ₂ and -CH _3, R
² -NH _2, is a monovalent atom or group selected from -COOH and -H, m is 1-2 integer, n represents an integer of 1 to 4. And a condensate of an aminonaphthalene compound represented by the formula: Specific examples of the aminonaphthalene compound represented by the general formula include, for example, β-naphthylamine,
3-amino-2-naphthoic acid, 3-amino-2-naphthol, 5-amino-1-naphthol, 1-amino-2-
Naphthol, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene, 2,3-diaminonaphthalene, 4-amino-2-methyl-1-naphthol and the like can be mentioned. Preferred among these are 3-amino-2-naphthol,
5-amino-1-naphthol, 1-amino-2-naphthol, 1,5-diaminonaphthalene, 1,8-diaminonaphthalene and 2,3-diaminonaphthalene. These may be used alone or in combination of two or more.

As a method of condensing an aminonaphthalene compound, for example, a solution condensation method of condensing an aminonaphthalene compound in a solvent in the presence of a catalyst can be mentioned.

Examples of the solvent include polar solvents such as dimethylformamide, N, N-dimethylacetamide, hexamethylphosphoric triamide, N-methylpyrrolidone, and nitrobenzene. These solvents may be used alone or in combination of two or more. They may be used in combination. When a low molecular weight condensate is obtained, water, alcohol or the like may be used in combination with these solvents.

As the catalyst, for example, iron chloride (II
Metal salts such as I), aluminum chloride, copper (II) chloride, potassium permanganate; persulfates such as ammonium persulfate;
Inorganic peroxides such as hydrogen peroxide; and oxidizing agents for organic peroxides such as benzoyl peroxide.

The condensation reaction of the aminonaphthalene compound is carried out at a temperature not higher than the boiling point of the solvent, usually at 10 to 150 ° C., preferably at 10 to 150 ° C.
Perform at 30-120 ° C. The reaction time may be usually 1 to 30 hours,
Preferably, it is 1 to 15 hours. After completion of the reaction, the reaction solution is poured into a poor solvent in an amount of 1 to 20 times the weight of the solution to precipitate a condensate, and the condensate is filtered and dried to obtain a condensate of an aminonaphthalene compound. . As the poor solvent for precipitating the condensate, for example, water, saline,
Ether, benzene, n-hexane, isopropanol and the like can be mentioned.

The reaction product of a condensate of an aminonaphthalene compound and p-benzoquinone is, for example, a condensate of an aminonaphthalene compound and p-benzoquinone, a condensate of an aminonaphthalene compound, p-benzoquinone and their reaction products. The reaction proceeds in a homogeneous system in which the reaction proceeds in a state in which the product is completely dissolved in the reaction solvent, or in a state in which the condensate of aminonaphthalene compound, p-benzoquinone and their reaction products are dispersed in the reaction solvent. It can be obtained by reacting in a homogeneous system. Examples of the solvent include polar solvents such as dimethylformamide, N, N-dimethylacetamide and acetonitrile; cyclic ethers such as tetrahydrofuran and dioxane; ketones such as acetone and methyl ethyl ketone; alcohols such as methanol, ethanol and isopropanol; Water and the like can be mentioned, and these can be used alone or in combination of two or more.

The ratio of condensate of aminonaphthalene compound / p-benzoquinone is usually 100/1 to 1/10, preferably 20/1 to 1/5 by weight. The concentration of the condensate of the aminonaphthalene compound and p-benzoquinone in the solvent is preferably 1 to 50% by weight in total. The reaction is carried out at a temperature lower than the boiling point of the solvent, preferably at 20 to 100 ° C. The reaction time may be generally 1 minute to 30 hours, preferably 1 to 10 hours. The reaction rate can be adjusted by, for example, adding a mineral acid such as hydrochloric acid, sulfuric acid or phosphoric acid; a base such as NaOH or KOH; preferably phosphoric acid to the reaction system. After completion of the reaction, the obtained reaction solution may be used as it is as a polymer scale adhesion inhibitor. In addition, the reaction solution was poured into a poor solvent in an amount of 1 to 20 times the amount of the solution to precipitate a reaction product, and the reaction product was filtered and dried, and the dried product was used as a polymer scale adhesion inhibitor. Is also good. Examples of the poor solvent for precipitating the reaction product include water, saline, ether, benzene, n-hexane, isopropanol and the like.

The polymer scale adhesion inhibitor of the present invention preferably contains an inorganic colloid in addition to the reaction product. Examples of the inorganic colloid include gold colloid, silver colloid, sulfur colloid, ferric hydroxide colloid, stannic acid colloid, silicic acid colloid, manganese dioxide colloid, molybdenum oxide colloid, barium sulfate colloid, water Aluminum oxide colloid,
Colloids of vanadium pentoxide, colloids of lithium silicate and the like can be mentioned, and these can be used alone or in combination of two or more. Among them, colloids of silicate and aluminum hydroxide are preferred. Particularly preferred silica colloids are aqueous silica sol, methanol silica sol, butanol silica sol,
Ethylene glycol silica sol and DMF silica sol. The blending amount of the inorganic colloid is such that the weight ratio of inorganic colloid / the reaction product (in terms of solid content) is usually 100/1 to 1/100,
Preferably, the amount is 10/1 to 1/10. If the amount of the inorganic colloid is too small, the advantage of the combined use may not be obtained.

The reaction product obtained by reacting such a condensate of an aminonaphthalene compound with p-benzoquinone has a lower activity of an amino group contained therein than a conventional aromatic amine condensate, and High molecular weight. When the activity of the amino group is low, the influence of the reaction product on the polymerization system of the monomer is small, and when the molecular weight is large, the amount of the monomer dissolved is small. Therefore, it is presumed that the polymer scale adhesion inhibitor of the present invention exhibits remarkable scale adhesion prevention properties.

(Method for Producing Polymer Using Polymer Scale Adhesion Inhibitor) The method for producing a polymer of the present invention is carried out in a polymerization vessel having a coating film comprising the polymer scale adhesion inhibitor on the inner wall of the polymerization vessel. And a method of polymerizing a monomer having an ethylenically unsaturated double bond.

The coating film is applied, for example, by coating a reaction solution containing the reaction product of the above-described aminonaphthalene compound condensate with p-benzoquinone as it is, or by applying a coating solution prepared as described below to the inner wall of a polymerization vessel and drying the coating solution. Can be formed.

Preparation of Coating Solution The coating solution is obtained by dissolving or dispersing the reaction product of the aminonaphthalene compound condensate and p-benzoquinone and, in some cases, an inorganic colloid in a suitable solvent.

As the solvent for preparing the coating solution, for example,
Water; alcohol solvents such as methanol and isobutyl alcohol; aromatic hydrocarbon solvents such as benzene, toluene and xylene; methylene chloride, dichloroethylene, 1,1,2
Halogenated hydrocarbon solvents such as trichloroethane; ketone solvents such as acetone and methyl ethyl ketone; ester solvents such as methyl formate and ethyl acetate; ether solvents such as 1,4-dioxane and ethylene glycol monomethyl ether; dimethylformamide; And polar solvents such as N, N-dimethylacetamide and N-methylpyrrolidone. These can be used alone or in combination of two or more. Among them, preferred are water,
Methanol, isobutyl alcohol, acetone, dimethylformamide or a mixture thereof. The concentration of the reaction product of the condensate of the aminonaphthalene compound and p-benzoquinone in the coating solution may be generally from 0.001 to 10% by weight, preferably from 0.01 to 2% by weight. Further, the coating liquid further containing an inorganic colloid preferably contains 0.01 to 5% by weight in total of the reaction product and the inorganic colloid (in terms of solid content). In addition, as a method of adding an inorganic colloid to the reaction product, after dissolving or dispersing the reaction product in the solvent, the solution or dispersion is preliminarily water, the solvent used in the coating solution, the inorganic An inorganic colloid having a concentration of 1 to 10% by weight is mixed with a colloid (solid content conversion) dispersion medium or the like.

Formation of Coating Film In order to form a coating film on the inner wall of the polymerization vessel using the prepared coating solution, first, the coating liquid is applied to the inner wall surface of the polymerization vessel, and then,
For example, after sufficiently drying in a temperature range from room temperature to 100 ° C., the inner wall surface of the polymerization vessel is further washed with water if necessary. In addition, it is preferable that the coating film is formed not only on the inner wall surface of the polymerization vessel but also on other portions where the monomer contacts during the polymerization,
Examples of such a portion include a stirring blade, a stirring shaft, a baffle, a condenser, a header, a search coil, a bolt, a nut, and the like. In addition, even if it is other than the site where the monomer comes into contact during the polymerization, the coating may be applied to the site where the polymer scale may adhere, for example, the inner surface of equipment and piping of the recovery system for unreacted monomer. It is preferable to form a film. Examples of such a portion include inner surfaces of a monomer distillation column, a condenser, a monomer storage tank, a valve, and the like. In order to form a coating film at the place, it may be performed in the same manner as when forming a coating film on the inner wall surface of the polymerization vessel.

As described above, when a coating film is formed on a portion where the monomer comes into contact during polymerization and a portion where the polymer scale may adhere to other portions, the adhesion of the polymer scale to those portions is reduced. Is prevented. The method of applying the coating solution to the inner wall surface of the polymerization vessel is not particularly limited. Examples thereof include brush coating, spray coating, a method of filling the polymerization vessel with the coating solution, and then extracting the solution.
JP-A-55-36288, JP-B-56-501116, JP-A-56-501117, and JP-A-59-11303 can also be used.

The method of drying after coating is not limited. For example, a method in which warm air heated appropriately after application is applied to the coating surface, the inner wall surface of the polymerization vessel to which the coating solution is to be coated, and other surfaces Previously heated to, for example, 30 to 80 ° C.,
A method of directly applying a coating liquid to the heated surface can be used. Further, when the boiling point of the solvent or the dispersion medium of the coating liquid exceeds 80 ° C., it may be dried under reduced pressure if necessary. After drying, the coated surface can be washed with water as needed. The coating thus obtained has a total coating amount after drying of usually 0.001 to 5 g / m
² , and particularly preferably 0.01 to 3 g / m ² .

The above coating operation may be performed for each one to several batches of polymerization. The formed coating has high durability,
Since the action of preventing adhesion of the polymer scale is maintained, the coating operation may be usually performed once every several batches. Thereby, the polymerizer can be used repeatedly without causing the polymer scale to adhere to the inner wall of the polymerizer.

Polymerization As described above, the coating is applied to the inner wall of the polymerization vessel and other parts where the monomer comes into contact during the polymerization to form a coating film, and then the polymerization is carried out in the polymerization vessel by a conventional method. That is,
In addition to monomers having an ethylenically unsaturated double bond and a polymerization initiator (catalyst), if necessary, a polymerization medium such as water, a suspending agent, a solid dispersant, a dispersant such as a nonionic or anionic emulsifier, etc. And then polymerization.

The monomer having an ethylenically unsaturated double bond to be polymerized by applying the method of the present invention includes, for example,
Vinyl halides such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; acrylic acid, methacrylic acid and their esters or salts; maleic acid, fumaric acid and their esters or anhydrides; butadiene, chloroprene, isoprene and the like Diene monomers; styrene; acrylonitrile; vinylidene halide; vinyl ether;

The type of polymerization to which the method of the present invention is applied is not particularly limited, and suspension polymerization, emulsion polymerization, solution polymerization,
It is effective in any of the polymerization modes of bulk polymerization and gas phase polymerization, and is particularly suitable for polymerization in an aqueous medium such as suspension polymerization and emulsion polymerization. The method of the present invention is particularly preferably applied to suspension polymerization or emulsion polymerization of a monomer mixture mainly composed of vinyl chloride; production of beads such as polystyrene, polymethyl methacrylate, and polyacrylonitrile, and latex; SBR, NBR , CR, IR, IIR, etc .; the production of synthetic rubber; the production of ABS resin; and the production of AS resin by suspension polymerization using a solid dispersant. Less than,
A general polymerization method will be specifically described.

First, water and a dispersant are charged into a polymerization vessel, and then a polymerization initiator is charged. Next, exhaust the inside of the polymerization vessel
After reducing the pressure to 0.1 to 760 mmHg, the monomer is charged (at this time, the internal pressure of the polymerization vessel is usually 0.5 to 30 kgf / cm ² · G), and then polymerization is performed at a reaction temperature of 30 to 150 ° C. During the polymerization, one of water, a dispersant and a polymerization initiator may be used, if necessary.
Add seed or two or more. Further, the reaction temperature during the polymerization depends on the type of the monomer to be polymerized, for example,
In the case of vinyl chloride polymerization, the polymerization is carried out at 30 to 80 ° C, and in the case of styrene polymerization, the polymerization is carried out at 50 to 150 ° C. The polymerization is performed when the internal pressure of the polymerization vessel falls to 0 to 7 kgf / cm ² · G.
Or it flows into the jacket equipped around the polymerization vessel,
Completion is determined when the difference between the inlet temperature and the outlet temperature of the cooling water to be discharged almost disappears (that is, when the heat generated by the polymerization reaction has disappeared). Water to be charged at the time of polymerization, a dispersant and a polymerization initiator are usually 20 to 500 parts by weight of water, 0.01 to 30 parts by weight of a dispersant, based on 100 parts by weight of a monomer,
The polymerization initiator is 0.01 to 5 parts by weight.

In the case of solution polymerization, an organic solvent such as toluene, xylene or pyridine is used instead of water as a polymerization medium. A dispersant is used as needed. Other polymerization conditions are generally the same as those for suspension polymerization or emulsion polymerization.

In the case of bulk polymerization, the inside of the polymerization vessel is about
After evacuating to a pressure of 0.01 to 760 mmHg, a monomer and a polymerization initiator are charged into the polymerization vessel, and polymerization is performed at a reaction temperature of -10 to 250 ° C. For example, in the case of polymerization of vinyl chloride,
The reaction is carried out at 80 DEG C. and in the case of styrene polymerization at 50 DEG to 150 DEG C.

When polymerization is carried out using the method for preventing adhesion of polymer scale of the present invention, adhesion of polymer scale can be prevented regardless of the material of the inner wall surface of the polymerization vessel. For example, even when the polymerization is performed in a polymerization vessel made of stainless steel or other steel, a polymerization vessel glass-lined, or the like, the adhesion of the polymer scale can be prevented. Those added to the polymerization system can be used without any restrictions. For example, t-butyl peroxy neodecanoate, bis (2-ethylhexyl) peroxy dicarbonate, 3,5,5-trimethylhexanoyl peroxide, α-cumyl peroxy neodecanoate, cumene hydroperoxide , Cyclohexanone peroxide, t-butylperoxypivalate, bis (2-ethoxyethyl) peroxydicarbonate, benzoyl peroxide, lauroyl peroxide, 2,4-dichlorobenzoyl peroxide, diisopropylperoxydicarbonate, α , Α'-azobisisobutyronitrile, α, α'-azobis-2,4-dimethylvaleronitrile, polymerization initiators such as potassium persulfate, ammonium persulfate, p-menthane hydroperoxide; partially saponified polyvinyl alcohol , Polyacryl Sulfonic acid, a copolymer of vinyl acetate and maleic anhydride, a cellulose derivative such as hydroxypropylmethylcellulose, and a suspending agent such as a natural or synthetic polymer such as gelatin; a solid dispersant such as calcium phosphate and hydroxyapatite; Nonionic emulsifiers such as laurate, sorbitan triolate and polyoxyethylene alkyl ether;
Anionic emulsifiers such as sodium alkylbenzenesulfonate such as sodium lauryl sulfate and sodium dodecylbenzenesulfonate; sodium dioctyl sodium sulfosuccinate; fillers such as calcium carbonate and titanium oxide; tribasic lead sulfate, calcium stearate, dibutyltin dilaurate, dioctyl Stabilizers such as tin mercaptide; lubricants such as rice wax, stearic acid and cetyl alcohol; plasticizers such as DOP and DBP; mercaptans such as t-dodecyl mercaptan; and chain transfer agents such as trichloroethylene; pH regulators; Even in a polymerization system in which a reducing agent such as iron is present, the method of the present invention can effectively prevent the adhesion of the polymer scale.

The polymer scale adhesion inhibitor of the present invention may be used for forming a coating film on the inner wall surface of a polymerization vessel and then added directly to the polymerization system. It can also be improved. In this case, the amount of the polymer scale adhesion inhibitor is suitably about 10 to 1000 ppm based on the total weight of the monomers to be charged. At the time of addition, care should be taken not to affect the quality of the product polymer such as fish eye, bulk specific gravity, particle size distribution and the like.

[0034]

The present invention will be described more specifically with reference to examples and comparative examples. (A) Preparation of condensate ( preparation of condensate of aminonaphthalene compound)

[Preparation Example 1] A 200 mL three-necked flask equipped with a stirring blade and a reflux condenser was charged with 31.6 g of 1,5-diaminonaphthalene and 50 mL of nitrobenzene, and stirring was started. Then AlCl ₃ · 6H ₂ O 2.4 g The solution was added dissolved in DMF 40 mL, the reaction was carried out for 5 hours at 80 ° C.. After completion of the reaction, the reaction solution was poured into 1000 mL of ether, and the precipitated condensate was filtered under reduced pressure, washed sufficiently with water, and dried at 50 ° C. The condensate thus obtained is referred to as condensate (A) -1.

[Preparation Example 2] The same three-necked flask as used in Preparation Example 1 was charged with 1,8-diaminonaphthalene 31.6
g and NMP (50 mL) were charged and stirring was started. Then 30% H
30 mL of ₂ O ₂ was added and reacted at 80 ° C. for 10 hours. After completion of the reaction, the reaction solution was poured into 500 mL of a 10% by weight saline solution, sufficiently washed with water, and then dried at 50 ° C. The thus obtained condensate is referred to as condensate (A) -2.

[Preparation Example 3] In the same three-necked flask as used in Preparation Example 1, 5-amino-1-naphthol 31.
8 g and 50 mL of nitrobenzene were charged and stirring was started.
Next, a solution in which 1.7 g of CuCl ₂ .2H ₂ O was dissolved in 50 mL of NMP was added, and the reaction was performed at 50 ° C. for 10 hours. After completion of the reaction, the reaction solution was poured into 300 mL of benzene, and the precipitated condensate was filtered under reduced pressure, washed sufficiently with water, and then dried in vacuo at room temperature. The condensate thus obtained is referred to as condensate (A) -3.

[Preparation Example 4] In the same three-necked flask as used in Preparation Example 1, 1,5-diaminonaphthalene 15.8
g, 5-amino-1-naphthol 15.9 g, DMF 50 mL
And stirring was started. Next, anhydrous aluminum chloride
A solution in which 1.3 g was dissolved in 30 mL of DMF was added, and the mixture was reacted at 100 ° C. for 5 hours. After the reaction is completed, the reaction solution is
The resulting condensate was filtered under reduced pressure, washed sufficiently with water, and dried at 50 ° C. The thus obtained condensate is referred to as condensate (A) -4.

[Preparation Example 5] In the same three-necked flask as used in Preparation Example 1, a reactor was charged with 15.8 g of 1,5-diaminonaphthalene, 15.8 g of 1,8-diaminonaphthalene, and DMF.
70 mL was charged and stirring was started. Then, FeCl ₃ · 6H ₂ O
A solution in which 2.7 g was dissolved in 30 mL of water was added, and the mixture was reacted at 80 ° C. for 10 hours. After completion of the reaction, the reaction solution was poured into 300 mL of isopropanol, and the precipitated condensate was filtered under reduced pressure.
After sufficiently washing with water, vacuum drying was performed at room temperature. The thus obtained condensate is referred to as condensate (A) -5.

(B) Preparation of reaction product ( preparation of reaction product of condensate of aminonaphthalene compound and p-benzoquinone) Condensates (A) -1 to (A) obtained in Preparation Examples 1 to 5 -5 and p-benzoquinone in the proportions shown in Table 1 and then
The reaction was carried out under the conditions (reaction solvent, catalyst, reaction temperature and reaction time) shown in Table 1 to produce reaction products (a) to (h).
For comparison, a non-condensed aminonaphthalene compound was replaced with p instead of a condensate of the aminonaphthalene compound.
-Reaction with benzoquinone to produce reaction products (i) to (k). The reaction product was obtained in a solution state. Reaction product
(b) and (f) were used in the Examples described later in the state of the obtained solution. Reaction products (a), (c) to (e), (g) and
(h) is, after completion of the reaction, 5% by weight of 10 times the volume of the reaction solution.
It was poured into a saline solution to precipitate a condensate, and the condensate was separated from the solution and made into a powder state, which was used in Examples described later. In Table 1, the reaction products marked with an asterisk (*) do not satisfy the conditions of the present invention and have been used in comparative examples described later.

[0041]

[Table 1]

(C) Preparation of Coating Solution As shown in Table 2, the component (I) selected from the reaction products (a) to (k) is dissolved or dispersed in a solvent in an amount shown in the same table. In some cases, the inorganic colloid component (II) shown in the table is added to and mixed with a solvent so that the compounding ratio (solid content) and concentration (concentration of the total amount of the reaction product and the inorganic colloid) shown in the table become, Coating liquid Nos. 1 to 25 were prepared. However, coating liquid
In Nos. 4 and 8, the reaction product was not used, but the condensate (A) -1 was used instead. The coating liquids marked with * are those that do not satisfy the conditions of the present invention and have been used in comparative examples described later.

[0043]

[Table 2]

Examples 1 to 9 and Comparative Examples 1 to 4 (when only one batch was subjected to a polymerization test) The inner wall, stirring shaft, stirring blades, and other single components of a stainless steel polymerization vessel with a stirrer (internal volume: 1000 L) Apply the coating solution (see Table 2) with the number (No.) shown in Table 3 to the part where the body comes into contact,
After drying at 50 ° C. for 15 minutes, the film was washed with water to form a coating film.
However, in Comparative Example 1, no coating liquid was applied. 400 kg of water, 200 kg of vinyl chloride, 250 g of partially saponified polyvinyl alcohol, 25 g of hydroxypropylmethylcellulose and 75 g of diisopropyl peroxydicarbonate were charged into the polymerization vessel, and polymerized at 57 ° C. for 6 hours with stirring. After the completion of the polymerization, the scale adhesion amount (g / m ² ) per unit area of the inner wall surface of the polymerization vessel was measured as follows. Table 3 shows the results.

Measurement method of polymer scale : Scales attached to an area of 10 cm square were scraped off with a stainless steel spatula and weighed as much as possible so that they could be visually confirmed.
The measured value was multiplied by 100 to determine the amount of scale adhering per 1 m ² .

[0046]

[Table 3]

Examples 10 to 16 and Comparative Examples 5 to 7 (when only one batch was subjected to a polymerization test) Using a polymerization vessel having an internal volume of 20 L, a coating solution (No.) shown in Table 4 (Table 2) Coating was formed on the polymerization vessel in the same manner as in Example 1 except that the above was applied. However, in Comparative Example 5, the coating liquid was not applied. In this polymerization vessel, 8k of water
g, styrene monomer 5.2 kg, methacrylic acid monomer 2.8
kg, 8 g of partially saponified polyacrylamide and α,
24 g of α'-azobisisobutyronitrile was charged and polymerized at 90 ° C. for 5 hours with stirring. After the polymerization, the amount of adhered polymer scale was measured in the same manner as in Example 1. Table 4 shows the results.

[0048]

[Table 4]

Examples 17 to 25 and Comparative Examples 8 to 11 (1
Polymerization test was conducted only for the batch.) The polymerization was carried out in the same manner as in Example 1 except that a coating solution (see Table 2) having the number (No.) shown in Table 5 was applied using a polymerization vessel having an internal volume of 22 L. A coating was formed on the vessel. However, in Comparative Example 8, no coating liquid was applied. In this polymerization vessel, 10k of water
g, styrene 2.5 kg, acrylonitrile 1.0 kg, SBR
2.4 kg of latex, 50 g of synthetic rubber emulsifier (trade name: Bandis T-100P) manufactured by Harima Chemicals, Inc., NaOH 2.0
g, 30 g of t-dodecyl mercaptan and 5.0 g of ammonium persulfate were charged and polymerized at 70 ° C. for 2 hours with stirring. After the completion of the polymerization, the amount of adhered polymer scale was measured in the same manner as in Example 1. Table 5 shows the results.

[0050]

[Table 5]

Examples 26 to 32 (in the case where a repeated polymerization test was carried out) A coating solution (see Table 2) having the number (No.) shown in Table 6 was applied using a polymerization vessel having an internal volume of 20 L. A coating film was formed on the polymerization vessel in the same manner as in Example 1. 9 k of water in this polymerization vessel
g, sodium dodecylbenzenesulfonate 225 g, t
-12 g of dodecyl mercaptan and 13 g of potassium persulfate were charged and, after purging with nitrogen gas, 1.3 kg of styrene and 3.8 kg of butadiene were charged and polymerized at 50 ° C for 20 hours. After the polymerization was completed, the polymer slurry was extracted, and then the inside of the polymerization vessel was washed with water. The process from application of the coating solution, polymerization, and washing with water was regarded as one batch, and 15 batches of polymerization were carried out. Then, the amount of adhered polymer scale was measured in the same manner as in Example 1. Table 6 shows the results. In this example, the scale adhesion amount was measured for a portion located in the liquid phase during polymerization and a portion located near the gas-liquid interface.

Comparative Examples 12 to 15 (when repeated polymerization tests were carried out) The same procedure as in Example 1 was carried out except that coating solutions No. 26 to No. 29 prepared as described below were used. A film was formed. Then, styrene and butadiene were polymerized in the same manner as in Example 20 using this polymerization vessel. After the polymerization was completed, the amount of polymer scale attached was measured in the same manner as in Example 1. Table 6 shows the results.

[Preparation of Coating Solution No. 26] 100 mL of a solution of 1,5-diaminonaphthalene / nitrobenzene dissolved in methanol at a weight ratio of 100/200 and a concentration of 1.0% by weight was added at 80 ° C. The mixture was stirred and reacted for 3 hours. To 20 mL of this reaction solution, 30 mL of methanol and 50 mL of water were added and mixed, and the pH was adjusted to 3.0 with HCl to obtain a coating solution.

[Preparation of Coating Solution No. 27] The weight ratio of 1,5-diaminonaphthalene / 1,8-diaminonaphthalene / p-benzoquinone was 30/30/40 and the concentration was 2.0% by weight. Solution 100 dissolved in 80 mL of methanol and 20 mL of water
mL was stirred at 30 ° C. for 10 hours to be reacted. This reaction liquid 10m
L, add 80 mL of methanol and 10 mL of water and mix.
The pH was adjusted to 11.0 with to prepare a coating solution.

[Preparation of Coating Solutions No. 28 and No. 29] To the above Coating Solutions No. 26 and No. 27 was added 3 g of an aqueous silica sol (20% by weight), and the mixture was mixed. The coating liquid was No. 29.

[0056]

[Table 6]

According to the method for preventing adhesion of polymer scale of the present invention, it has been difficult to prevent adhesion of polymer scale because of its high solubility in a coating film formed with a polymer scale adhesion inhibitor. In the polymerization or copolymerization of the monomer having an ethylenically unsaturated double bond, the adhesion of the polymer scale to the inner wall surface of the polymerization vessel or the like can be effectively prevented. Particularly in the polymerization system containing a monomer such as styrene, α-methylstyrene, acrylic acid, acrylate, acrylonitrile, etc., having a remarkably large dissolving ability with respect to the conventional coating film, it is possible to surely prevent the adhesion of the polymer scale. it can. In addition, the formed coating film has high durability, and the action of preventing the adhesion of the polymer scale is maintained, so that the polymerization vessel once formed with the coating film can be used repeatedly, and thus the production can be performed. Performance can be improved. In addition, in the conventional polymer scale adhesion inhibitor, the polymer scale in which the inner wall surface is glass-lined was more likely to adhere to the polymer scale than the stainless steel polymerizer, but the polymer scale adhesion inhibitor of the present invention was used. The use of a polymer can effectively prevent adhesion of the polymer scale regardless of the material of the inner wall of the polymerization vessel.

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-53-13689 (JP, A) JP-A-3-26704 (JP, A) JP-A-1-135802 (JP, A) JP-A-2- 158601 (JP, A) JP-A-5-178910 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08F 2/00-2/60 WPI (DIALOG)

Claims (3)

(57) [Claims] 1. A condensate of an aminonaphthalene compound and p-
A polymer scale adhesion inhibitor for the polymerization of a monomer having an ethylenically unsaturated double bond containing a reaction product with benzoquinone. 2. The polymer scale adhesion inhibitor according to claim 1, further comprising an inorganic colloid in addition to the reaction product. 3. A method for producing a polymer, comprising a step of polymerizing a monomer having an ethylenically unsaturated double bond in a polymerization vessel having a coating film having a polymer scale adhesion preventing property on an inner wall of the polymerization vessel. A method for producing a polymer, wherein the coating film having the polymer scale adhesion preventing property comprises the polymer scale adhesion preventing agent according to claim 1 or 2.